Many
studies have reported both genetic and environmental effects
on attention problems. However, such studies have not tested
the longitudinal stability of genetic and environmental effects
over multiple developmental periods. The Netherlands Twin
Register (NTR) is a unique resource that has been obtaining
assessment data for thousands of Dutch twins since 1987. The
NTR's use of ASEBA instruments to assess twins at many ages
enables researchers to test genetic and environmental effects
during different developmental periods, as well as testing
the longitudinal course of such effects from one developmental
period to another. Kan et al. (2013) used CBCL ratings by
parents of 3- to 12-year-olds, YSR self-ratings by 12- to
18-year-olds, and ASR self-ratings by18-90-year-olds to conduct
such tests. The researchers found that the heritability and
longitudinal stability of ASEBA Attention Problems scores
were highest in childhood and lowest in older adulthood. Although
both genetic and environmental effects contributed to stability
from one developmental period to another, changes were primarily
due to environmental factors, especially "innovations,"
which are effects that influence attention problems at particular
points in development but that are not predictable from previous
measurements. As Kan et al. concluded, their findings "that
environmental innovations were ubiquitous suggests an accumulation
of different lasting environmental effects on AP (Attention
Problems). Therefore, although short-term prediction of AP
is possible, the long-term prediction is difficult" (p.
21).